Please help me I just can’t figure this out. I’ll mark you brainiest if you know it but ONLY if you know it

Step-by-step explanation:

All square angles are 90° exactly 90° so we can use that to your advantage. since "7x + 3" is one of the square's angles, that means 7x + 3 must equal 90°. (7x + 3)° = 90°.

7x + 3 = 90

7x = 90 - 3

7x = 87

7x/7 = 87/7

x = 87/7

step-by-step explanation:

#15. square

step-by-step explanation:

because quadrilatural (idk how to spell it) means somthing that is not 3d or like, equal sides (or somthing like that   you know what i meanz)

hope this halps!

bai!